/*
 * Copyright (C) 2010 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect;

import static com.google.common.collect.DiscreteDomain.integers;

import com.google.caliper.BeforeExperiment;
import com.google.caliper.Benchmark;
import com.google.caliper.Param;

import java.util.Set;

/**
 * Very simple powerSet iteration benchmark.
 *
 * @author Kevin Bourrillion
 */
public class PowerSetBenchmark
{
    @Param({"2", "4", "8", "16"})
    int elements;

    Set<Set<Integer>> powerSet;

    @BeforeExperiment
    void setUp()
    {
        Set<Integer> set = ContiguousSet.create(Range.closed(1, elements), integers());
        powerSet = Sets.powerSet(set);
    }

    @Benchmark
    int iteration(int reps)
    {
        int sum = 0;
        for (int i = 0; i < reps; i++)
        {
            for (Set<Integer> subset : powerSet)
            {
                for (Integer value : subset)
                {
                    sum += value;
                }
            }
        }
        return sum;
    }
}
